Seriously, if you are intending to do this yourself you need to get item called a 'spade bit' or possibly a 'spear bit'. These are designed for glass and ceramic. If you can, I would suggest that you practice as much as you can before trying it for real. If the item to be drilled is important or valuable I would consider getting it professionally done.
I bought a set of spade bits for drilling ceramic tiles last year. I imagined more broken tiles but I was really impressed with how easily they drilled perfect holes through tiles. I'm sure they would go through glass as easily - after all, they are designed to do just that. Being careful is the key though Groupie!